Lubricant composition



Patented Oct. 28, 1947 UNITED STATES PATENT OFFICE LUBRICANT COMPOSITIONNo Drawing. Application September 10, 1943,

Serial No. 501,855

1 Claim. (CL 252-52) The present invention relates to lubricants ofimproved quality. More particularly, the invention concerns improvedlubricant compositions for use in certain types of service whereinoperating conditions are such as to tend to cause rusting of equipment.

There are certain types of operation requiring lubrication of metalsurfaces in which the service equipment is prone to rust due to thepresence of water. In such operations, it is desirable, and oftenmandatory, that the lubricant serve not only as a lubricating agent butalso asa rust preventive agent. In order for the lubricant to fulfillthe latter function in satisfactory manner it must be capablepreferentially of wetting the metal surfaces under prevailing operatingconditions so that a protective coating of lubricant will form andprevent effective contact between the metal and water.

An outstanding example of a case where th lubricant should function asan anti-rust agent as well as a lubricant occurs in the operation ofsteam turbines. Due to the elevated temperatures employed in turbineoperations and to the presence of water formed through condensation ofthe steam, steel surfaces within the turbine or gear case are prone torust. In cases where the lubricating oil has insufilcient protectivequality the metal surfaces may become so badly rusted as to scale ofi,causing scoring of bearings, sticking of governor mechanisms, pluggingof oil lines, etc., often resulting in severe economic loss. A trend inturbine developments within 'recent years toward higher operatingtemperatures and pressures has placed increasingly greaterrequirementson the turbine oils, with the result that oils which weresatisfactory some years ago are now unsuitable in many cases, if notgenerally. Oils refined in accordance with usual present-day practicegenerally lack preferential wetting characteristics necessary to impartthe desired rust-preventive qualities.

The present invention is directed to and provides lubricant compositionswhich have the desired rust-preventive characteristics. In accordancewith the invention the aforesaid rust-preventive quality is obtained inthe highest degree by incorporating in the lubricant composition asubstance comprising a relatively small amount of an oil-soluble,water-insoluble substituted 1,2-dihydroxy-benzene, preferablyderivatives of pyrocatechol (1,2-benzenediol) having an alkyl groupattached to the benzene ring in the para position. I have discoveredthat substances of this type when added to lubricating oil in relativelysmall proportion impart to the resulting composition the ability toprevent rusting of metallic surfaces, presumably due to preferentialwetting of the surfaces by the lubricant composition.

As examples of effective rust-preventing agents of the type above setforth may be mentioned the following: 4-tertiary butyl-1,2 benzenediol;4-tertiary octyl-1,2 benzenediol; 4-

. lauryl-l,2-benzenediol; and 4-cyclohexyl-l,2 benchains are such as toimpart to the compounds the desired solubility characteristics. Thesecompounds may be used in any effective proportion. but it is generallysatisfactory to employ relatively small amounts, for example, not over 2per cent and preferably 0.1-0.5 per cent. The stearyl derivative ofpyrocatechol, which contains eighteen carbon atoms in the attachedstearyl group, although having the desired solubility characteristics,is not as effective as the above named agents and therefore must be usedin a greater proportion in order to afford the desired protectiveaction. The lower efiectiveness of the stearyl derivative presumably maybe due to too large a number of carbon atoms in the attached hydrocarbongroup; accordingly it is preferred to use derivatlves having fewercarbon atoms in the attached group, for instance 4-12 carbon atoms.

The following examples are given by way of illustration of the inventionbut are not to be taken in limitation thereof since many modificationsobviously are within the purview of the invention:

An acid-treated and clay-filtered turbine oil stock having the followingspecifications:

Gravity A. P. L- 22.5 Flash point F 335 Fire point F 380 SayboltUniversal vis. at F N. P. A. color Per cent of ggs specimen surfacerusted Turbine oil stock Failed 80 Turbine oil stock +02% 4-tertiarybutyl-l, Passe 2 benzenediol. Turbine oil stock +02% 4-tertiary oetyl-l,-do... 0

2 benzenediol. Turbine oil stock +02% 4-lauryi-l, 2 do.. 0

benzenedioi. Turbine oil stock +0.l% 4-cyciohexyi-l, do.. 0

2 benzenediol.

The above tabulation clearly shows that all 01 the addition agentseifectively prevent rusting. In the appended claim whenever reference ismade to a substituted dihydroxy-benzene, it should be understood thatthis refers to a compound resulting from replacement of nuclear hydrogenin a dihydroxy-benzene by at least one hydrocarbon group.

What I claim and desire to protect by Letters Patent is:

A lubricant composition adapted for use under service conditions in thepresence of water to prevent rusting due to contact between metal andwater which consists essentially of lubricating oil and 0.1 %-2.0% of anoil soluble, water-insoluble 1,2 dihydroxybenzene having an alkyl groupattached to the benzene ring selected from the group consisting of4-tertiary butyl-1,2 benzenediol; 4-tertiary octyl-1,2 benzenediol;4-lauryl-1,2 benzenediol and 4-cyclohexyl-1,2 benzenediol.

WORTLEY ANDREW WRIGHT.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,793,135 Rogers Feb. 17, 19311,942,827 Mills Jan, 9, 1934 2,046,900 Ipatiefl July 7, 1936 2,116,220Shoemaker May 3, 1938 2,194,312 Loane Mar. 19, 1940 2,197,833 Reifi Apr,23, 1940 2,197,835 Reifi Apr. 23, 1940 2,298,638 Prutton Oct. 13, 19422,316,903 Van Ess Apr. 20, 1943 2,326,496 Reiff Aug. 10, 1943 2,339,797Musher Jan. 25, 1944 2,352,669 Van Ess July 4, 1944 2,388,887Weissberger Nov. 13, 1945 FOREIGN PATENTS Number Country Date 819,608France Oct. 22, 1937

